Yesterday a mix of people who own Google Pixel phones and other devices running Android 9 Pie noticed that the software’s Battery Saver feature had been switched on — seemingly all by itself. And oddly, this was happening when the phones were near a full charge, not when the battery was low. As reported by Android Police, initially it was assumed that this was some kind of minor bug in the latest version of Android, which was only released a few weeks ago. Some users thought they might’ve just enabled Battery Saver without realizing.

But it was actually Google at fault.

The company posted a message on Reddit last night acknowledging “an internal experiment to test battery saving features that was mistakenly rolled out to more users than intended.” So Google had remotely — and accidentally — changed a phone setting for a bunch of real-world customers. Several staffers at The Verge experienced the issue. “We have now rolled battery saver settings back to default. Please configure to your liking,” the Pixel team wrote on Reddit before apologizing for the error.

It makes sense that Google has this capability, but it still shouldn’t have happened

This wasn’t just limited to Pixel phones, however; devices including the Essential Phone, OnePlus 6, Nokia handsets, and others running Pie (even in beta form) switched Battery Saver on without any user action. According to Google, when active, Battery Saver:

Stops apps from refreshing content until you open them

Stops use of location services when the display is off

Prevents apps from doing things in the background

Delays some notifications

So that might’ve resulted in some frustration for users who didn’t even realize it was on.

Both Apple and Google have emergency means of forcing updates or making other changes to iOS and Android, respectively. It’s a necessary option to have at their disposal for user safety and security, and it’s not a new one. Way back in 2008, Steve Jobs confirmed that Apple had a kill switch option for malicious apps; he told The Wall Street Journal “hopefully we never have to pull that lever, but we would be irresponsible not to have a lever like that to pull.” But it’s the silent and invasive nature of Google’s mistake that’s bothering people.

You’d hope there would be more walls between internal Android tests at Google and the Android OS that customers are using daily on their personal devices.